Carts and dollies are often used in textile factories and textile mills to transport textile and other objects from one work or storage station to another. Those carts are often provided with casters, which enable the cart to roll. Textile mills may have loose threads and fibers on the floor of the work or storage areas. Many conventional casters permit the loose thread to become tangled on the axle and in the bearings and thereby inhibit the rolling of the caster.
Some caster designs have attempted to inhibit thread from entering the axle area and tangling on the axle. An example of such a design is disclosed in U.S. Pat. No. 2,742,663. Although that design does, to some extent, inhibit thread from tangling around the axle, the design does not entirely prevent thread wrap. Allowing some threads into the caster assembly was not often a severe problem when cotton and other natural fibers were used. These natural fibers pose little risk of jamming or damaging the caster because they tend to break down and decay from the friction and other forces present in the axle area. In contrast, modern, synthetic fibers do not tend to break down and decay. Instead, these much tougher fibers will clog the caster and may even cut through the plastic wheel, mar the metal axle, or damage a wheel bearing Thus, keeping these fibers out of the caster assembly is of even greater importance.
Moreover, previous caster designs were difficult to disassemble and clean when thread did become tangled around the axle. Those casters are not comprised of individual replacement parts such that each component part could be taken out, cleaned and replaced individually if it was worn or otherwise had failed to operate. Instead, entire portions of the assembly must be replaced.
In addition, those designs do not provide inner and outer support for the bearings. The bearings are therefore susceptible to damage caused by lateral forces exerted in directions other than in the plane in which the bearing is intended to turn. These forces may cause the bearing to shift its position along the axle and can cause excessive bearing wear.
Accordingly, it is an object of the present invention to provide a caster assembly including a wheel retaining hub and axle portions that inhibit thread and lint from becoming wound around the axle and bearing.
Another object of this invention is to provide a thread inhibiting caster assembly that contains a small number of parts, so that the caster can be easily assembled and disassembled.
It is a further object of this invention to provide a thread inhibiting caster assembly in which each component part can be individually and easily replaced should it become worn.
Still another object of the present invention is to provide a thread inhibiting caster assembly including a bearing support to prevent the bearing inner race from shifting locations on the axle, and to reduce bearing wear resulting from lateral forces on the caster assembly.
Another object of the present invention is to provide a thread inhibiting caster assembly including a bearing stop associated with the wheel that centers the bearing within the wheel, and provides support for the outer race against lateral forces.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.